A potential security exposure is due to the Java HashTable implementation, which can result in a Denial of Service (DoS).
Diagnosing the problem
A security exposure exists in all versions of WebSphere Application Server, which have shipped with WebSphere Enterprise Service Bus. This issue can cause a large number of HashTable collisions due to specially crafted HTTP request parameters. With too many collisions, performance is significantly impaired and can lead to a denial of service.
Resolving the problem
For the most up-to-date information, review the following WebSphere Application Server document: Potential security vulnerability when using Web based applications on IBM WebSphere Application Server due to Java HashTable implementation vulnerability (PM53930)